Thread bunching
 

I am piecing a block with is triangles. At the beginning of the sewing the needle eats my material and bunches up the thread on the bottom material and will not continue on with the seam. I have done all the things like checking the needle and threading on top and bobbin. It is all correct. Any suggestions?

Are you holding your thread tails as you begin sewing?

First, welcome to the board!
This is a common problem. There are several things you can do. First, I'm guessing that you have a zigzag needle plate. This has a wide opening to accommodate the back and forth movement of the needle. You should see if there is a straight stitch needle plate available for your machine. This has a small circular hole which supports the fabric and lessens the chance of it being eaten.
Next, you need to either hold both thread tails to the back of the machine as you begin stitching or use a leader (aka, startie-stoppie or spider). This is a scrap of straight fabric that you start to sew onto, then chain piece your triangles after. When you get to the end of your chain, snip the leader off and sew onto it so you are ready for the next chain.

One thing I find very helpful when piecing is to use a leader and ender (believe this is what they are called). You can google this and believe you will be able to find a video showing how these are used to begin your piecing which eliminates the puckering at the beginning. This has been discussed here on the board several times. Hope this helps.

Are your feed dogs engaged? I would look and make sure they are working properly.

What PaperPrincess said is what I do. i have little pieces of fabric by my machine and use them especially when piecing small triangles. I call them "starters", I find that it is easier than holding the threads because I am using my hands to make sure that my fabrics are in the right place.

Welcome to the board :) As others have suggested, leaders and enders are probably your best bet.

Triangles are notorious for 'disappearing' down the plate, especially with the new wider stitch widths. You could try a straight stitch plate and see if that helps.

These are good suggestions.
Many of us who sew with non-computerized machines sometimes forget that the 'thread take up lever' -- on the front of the machine that lifts the thread before it goes into the needle -- needs to be in the "all the way up" position before starting to sew. When it isn't, it tends to grab the bobbin thread and that cause a bunch or knot underneath the fabric. To make sure the lever is up, you can hand turn the wheel on the end of your machine -- ALWAYS toward you -- before you begin to sew.

Jan in VA

Welcome to the board. You either have to hold your threads before you make that first stitch or use the piece of excess fabric called "leader or ender" especially when doing a lot of chain stitching.

You should use a scrap as a leader first cuz then the thread would be on the scrap
nancy from CA